This invention is directed at water resistant pesticide compositions such as baits and granules.
Pesticidal baits are traditionally formulated with active pesticides and/or attractants, onto an inert substrate which is palatable to the targeted pest. Desirable inert substrates include sugar, ground corn cob, corn meal, oatmeal, etc. These substrates are water soluble or they are very hydroscopic. This property limits where the bait can be used and how long it will last, depending on the amount of moisture available. An object of this invention is to provide a means to render pesticidal baits water resistant, thereby expanding the environment in which they can be used and extending the time of their activity over that of non-water resistant pesticidal baits.
Pesticidal granules are traditionally formulated on mineral or cellulosic substrates such as clay, diatomaceous earth, silica, corn cob, peanut hulls, paper, etc. These materials tend to be hydrophylic or hydroscopic or if hydrophobic they do not adsorb liquids except on the surfaces. If the pesticides are on the surfaces they are frequently removed when placed in contact with water or they are chemically degraded reducing their useful life. If the materials are hydrophylic they tend to cake when they become wet and function as moisture trap which maintains a humid environment in their immediate area as well as degrading the pesticide. These factors become very important in outdoor equipment in that: 1.) the equipment is visited infrequently thus requiring long lasting insect control for protection of the equipment and 2.) temperature cycling creates moisture condensation, which is held and released over time by the granule to create an ideal corrosive environment in enclosed equipment. While there are numerous means of applying pesticides in such a manner that circumvent the negatives associated with granules, they are expensive and the convenience of a granule product is lost. This invention describes a means of using traditional granule materials and circumventing the moisture problems described above by making the granules water resistant or waterproof.